take a look at this picture. you cant tell me that the caps between valves are different sizes
2. 3" PVC plug. Square face, about 3/8" thick allowed tapping 1" pipe threads 1 3/4" apart for assembly of two valves. Info to follow sometime on how to build this close-quarter dual-valve assembly.
6. Forward 3" PVC plug same as #2.
7. 2 1/2" x 3" bushing turned to ride inside reamed out 3" tee (loading area) and rear edge to jamb and seal against end of forward 3" plug.
all of that is taken directly from the site. on the SP9202 i do agree that that the T and the back cap look to be different sizes. i just realized that we are talking about different cannons. i was talking about the one built for the army, you are talking about the other one. and i think that you are correct about it being a 2.5 inch T. either way, do it the way that i described in the earlier post and you will be just fine. thats all for now, sorry bout the confussion,